This invention relates to a method of controlling broadleaf weeds in turf using an herbicidally effective amount of an acetolactate synthase (ALS) inhibiting herbicide. More particularly, when applied as a solid granular formulation, ALS inhibiting herbicides are safer to desirable turf species.
The search for compounds which have a combination of excellent herbicidal activity towards target weeds and low toxicity towards non-target plants is a continuing one because of factors such as the desire for compounds exhibiting greater activity, better selectivity, lower undesirable environmental impact, lack of phytotoxicity to the locus of application, lower production and market cost and higher effectiveness against weeds resistant to known herbicides. In particular, there exists a need for effective control of broadleaf weeds in turfgrass. Commercial herbicides, for example, 2,4-D, mecoprop-P, clopyralid, triclopyr and methylarsonic acid, have serious deficiencies such as requiring a high application rate to be effective, possessing less than desirable environmental profiles, having too great or too poor soil mobility and/or being toxic to non-target plants and or turfgrass species.
Herbicides that inhibit acetolactate synthase (ALS) have recently been found to effectively control broadleaf weeds in turfgrass at relatively low application rates; however, even at the low doses required to control the broadleaf weeds, some stress is often observed in many non-target turfgrass species. It would be desirable to have a method for making the ALS inhibiting herbicides less phytotoxic to the turfgrass without substantially affecting there control of broadleaf weeds.